Chosen Solution
I have trouble with my k-cup spitting grounds inside the machine where the k-cup sits during brewing. I don’t believe the problem is the puncture needles or the top gasket. I have cleaned and checked both of these, many times, and the needles seems to be puncturing normally. I think the problem is the k-cup ITSELF. I have observed that, in about 2-3 out of every 5 cups, the top rim of the k-cup actually separates… so, the leakage is not coming from the needle hole area. The leakage is coming from the edge of the k-cup. It is as if there is too much pressure INSIDE the k-cup during brewing, which forces the top covering of the k-cup, causing it to separate from the plastic cup.
@ljpne to much air inside the k-cups can cause this but that would be a manufacturer defect which we cannot fix. Change your brand and where you buy the K-cups. See if it continues. If your K-Cups have a domed, rounded top use a small needle and puncture the top before using it in your Keurig If it does, you do want to clean the puncture needles. your Keurig has two, one on top and one on the bottom, If anyone of these two is clogged you will get a K-cup explosion due to excessive pressure inside the cups. I would start by cleaning the puncture needles since that would be the easiest fix. How to open and clean Keurig Coffee Maker
Previous answer is bad advice. If the foil lidding is separating it is because of inferior sealing. This could be caused by a few reasons. My suspicion is that you have purchased clones rather than original Keurig brands. Thermal sealing done by packaging equipment other than Keurig Incorporated can be less reliable. It could also be a polypropylene compatible issue from a Chinese manufacturer of knock off cups. (Water temperature from brew cycle causes seal to fail) Either way, there is a high probability that this is a defective cup purchase. If it continues after you try different capsules, please continue thread and I can offer a final suggestion. Darren
I have been using genuine k-cups for years and have on occasion found the lid separating from the cup. Recently, it has been happening much more frequently. Usually the lid separates about half way through the brew cycle. The bottom and top needles are always clean. I too believe this to be the result of an inferior seal. As recommended by others, I purchased some thin foam sheets ( about 1/8” thick) from the dollar store and cut out a donut shape (large hole in the middle) slightly larger than the top diameter of the k-cup. I place the donut shaped piece of foam over the top of the k-cup when closing the top. This seems to apply enough pressure in most cases to keep the top of the k-cup from opening. The idea being to apply a little more pressure to the top of the cup. This makes it a little more bothersome to make a cup of coffee, but I get to keep using my Keurig.
The overpressure condition is caused by the inner filter popping, leaking grounds and clogging the bottom needle. The water being pumped by the coffee maker has nowhere to go so the pressure is enough to pop the top seal. I cut open some different pods to see the construction of them. I found that the Starbucks brand has an added filter shield under the filter pod. It has holes to allow the coffee to go through, but supports the filter pod from popping. I also found that many brands of pods have a larger filter pod inside. The larger filter pod hangs low enough that the bottom needle of the coffee maker can pierce the filter and cause it to leak grounds.
